Electrical welding of sheet metal.



E- THOMSON.

BLECTBICAL WELDING OF SHEET METAL.

APPLICATION IILEI) 00121, 1909.

1,078,225, Patented Nov. 11, 1913,

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nniniiirnoivi'sofior swAivrPscoT'nTaAssAoHUsE'rtrs, ASSIGNOR, BY MESNEASSIGN- MENTS, TO THOMSON ELECTRIC WELDING COMPANY, or LYNN,MASSACHUSETTS,

A CORPORATION OF MASSACHUSETTS.

ELECTRICAL WELDING OF SHEET METAL.

To (/77 whom. it may concern lle it known that I, ELIIIU THOMSON, a

citizen of the United States, and a resident of Swampscott, in thecounty of Essex and State of Massachusetts, have invented certain newand useful Improvements in Electrical llelding of Sheet Metal, of whichthe following is a specification.

My invention relates to that class of metal work in which plates orsheets of metal are united by spot welds as described in the patent toA. F. Rietzel, No. 928,701, dated July 20th, 1909.

The object of my invention is to permit work of that character to bereadily and economically produced by the use of pieces of metaloperating to localize the heating and pressure in the point or points ofwelded union.

Briefly stated, my invention consists in the provision of a string orchain of metal pieces eachof which is adapted to localize the electricheating and area of each spot weld while the connections between saidpieces are adapted to predetermine the spacing and relative location ofthe spots either or both.

In the accompanying drawings, Figure 1 shows in plan two sheets orplates of metal and a string or chain of pieces of metal adapted for usein welding said plates or sheets together by the spot welding processaforesaid. Fig. 2 shows said plates or sheets superposed or lapped andwith the pieces of metal interposed and in position which they wouldoccupy when the two plates are placed between the welding electrodes.Fig. 3 illustrates a modification in the form of the connection betweenthe pieces. Fig. .4 shows a string or chain of pieces arranged todetermine their spacing and relative disposition so as to determine thelocation of the spots of welded union within the boundaries of the plateor sheet of metal to be united to the surface of another plate.

Referring to Fig. l, the ends of the two sheets of metal to be united ontheir opposed lapped surfaces are indicated by the numeral 2, while 3indicates a string or chain of small disks or pieces of metal connectedSpecification of Letters Patent.

Application filed October 21, 1909.

Patented NOV. 1 1, 1913. Serial No. 523,766.

by links or connecting portions 4. Said pieces 3 may be of sheet metaland the connections 4 whereby they form a string or chain of pieces maybe of any material de sired and flexible or not, as found conven ient.The connections 4 may be of some substance which would be fusible orotherwise destructible inthe process and either wholly or merely attheir points of connection with the pieces, or they may be very fine orthin strips of metal which may be somewhat thinner than the pieces 3. sothat the electric welding current would be more fully confined to thepieces 3. Conveniently, the chain of pieces may be cut from sheet metal,the intermediate portions 4 being thin or not, as found desirable. Theassembling of the pieces 2 with the pieces 3 interposed for welding isshown clearly in Fig. 2. The pieces 3 might also be connected up into aring or endless chain or string, as illustrated in Fig. 4 and theconnections 4 might be sufficiently stiff to practically determine therelative position of the pieces 3 to one another, as well as theirdistance apart, when they are placed upon the sheet of metal 2, tolocalize the welding of the same to an opposed sheet or plate at spotscoincident with the pieces 3.

The manner of connecting the uniting parts 4 to the pieces 3 obviouslyforms no part of my invention. In the case of the arrangement shown inFig. 4 as well as in the other cases, the whole chain may be formed bystriking it up from sheet metal.

Obviously, my invention is not confined to the exact shape of thecontact pieces and their connections and many variations may be made inthe same without departing from my invention.

What I claim as my invention is:

1. A string of contact pieces for electric spot welding, each said piecebeing adapted to localize the electric heating and area of each spotweld to the desired extent in the surface of the welded pieces and themembers of said string being connected to one another by comparativelynarrow spacing connections adapted to predetermine the spacing of thespots of welded union.

2. A strin of electric contacts for elec- Si ned at Lynn in the countyof Essex tric spot We ding consisting of pieces of and tate ofMassachusetts this 19th day of sheet metal joined by comparativelynarrow October A. D. 1909.

sheet metal spacing connections integral ELIHU THOMSON. 5 With them,said connections bein of length Witnesses:

to predetermine the spacing of the spots of JOHN A. MoMANUs, J r.,

Welded union. ROBERT SHAND.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Iatents, Washington, D. O.

